In internal combustion engines, variable valve timing (VVT) describes mechanisms and related methods that can be used to alter the shape or timing of a valve lift event within an internal combustion engine. VVT engines allows the lift or timing of the intake and/or exhaust valves to be changed during operation of the engine.
In a VVT engine, the rotor and the stator often have a complex shape. In particular, the rotor body typically includes a main body with vanes, channels for oil or air transport, and a central bore hole for assembly to the camshaft. The vanes, in combination with the stator housing, define variable oil or air pressure chambers inside a stator housing. The channels allow for the oil or air transport from one pressure chamber to other pressure chambers.